2008-2-PHI130.Week03

Week 3: Plato's Doctrine of Forms

Readings

Plato, Republic

Plato, Republic, Section VII, 514-521, p.376-383; Section X, 596-598, p.468-471. In The dialogues of Plato, vol.II, trans. by B. Jowett (Oxford: Clarendon Press, 1964).

Plato, Timaeus

Plato, Timaeus, trans. D. Lee (Harmondsworth: Penguin Books, 1977), p.72-79

The many faces of science

L. Stevenson and H. Byerly, The many faces of science (Westview Press, 1995), p.52-63.

Ideal cities

R. Eaton, Ideal cities (London: Thames and Hudson, 2001), p.196-204.

Lecture Notes

Book X: The three beds

While Socrates put philosophy on its way, Plato is the first real philosopher in the sense that he endeavours a systematic coverage of all aspects of reality. He offers and explanation for all the different spheres of reality with political, moral, scientific, and aesthetic implications.

We will look at two of the most famous aspects of his thinking:

• His theory of ideas
• His theory of love

Plato's doctrine of forms, or doctrine of ideas, asks a metaphysical question about what is real and how we can know it. He endeavours to answer this by trying to look beyond what is available to the senses to find the ultimate level of reality. Once defined he then seeks to determine how we can know about this ultimate level of reality.

Book X (Ten) of Plato's famous book The Republic is where we learn of his theory of forms. The Republic is his longest book, and it's a book of political philosophy that deals with what is a just city. In order to know what a good city is we need to know what reality is and how we can know about it. That is, we must answer the fundamental questions in order to know what a just city is.

In The Republic Plato speaks through Socrates, but we understand that these are likely Plato's ideas and not those of Socrates.

Two equivalent Greek words: eidos or idea = Form or Idea.

The thought is that we use the same name for different things. E.g. "chairs", even though they are all different in some respect.

What is beauty? Things, persons, emotions. We use it with the same meaning in all these contexts. How do we know the meaning of the adjective remains the same?

The concept that Plato draws out is that there are two levels of reality at the very least. There's the physical level in the material world, and above that the notions or concepts of these things.

Aristotle criticised Plato for his ideas (we get to that later).

Plato held the ideal world out as being more 'perfect' than the physical world. This is very similar to Pythagoras' idea that the material world is a world of corruption where the world of ideas is a world of perfection.

This is one of the most famous texts of Western philosophy, the simile of the three beds:

• The ideal
• The realisations of the ideal
• The appearances of the realisations

In a just city Plato would expel the poets, because they lie in representing things that they don't know about.

Book VII: the allegory of the Cave

The Good is principle of order in the world and in knowledge.

The Divided Line.

DOXA (opinion) EPISTEME (science) Knowledge Eikasia Pistis Dianoia Noesis Objects Appearances Visible things Mathematical terms First principles Ideas of things The Good VISIBLE THINGS INTELLIGIBLE THINGS

Eikasia

illusion, conjecture about appearance of visible things.

Pistis

perceptual belief about visible things.

Dianoia

Knowledge that starts from a hypothesis and moves from it through analysis (i.e. without recourse to visible things, without empirical considerations), to conclusions. Model is mathematics, geometry, astronomy. This type of knowledge is unable to justify its own hypotheses.

Noesis

First it is a type of reasoning. Dianoia starts from hypotheses that are the Forms of physical things. In this sense, Dianoia still relies on the physical world. For example, the mathematician uses a triangle drawn in the sand.

By contrast, Noesis is pure thought which no longer uses images of the visible world. Hypotheses now are pure ideas. The mind ascends gradually to the first principle, the Idea of the Good, the normative principle of knowledge and reality. Once the first principles has been seen, after this ascending movement, reasoning can redescend and redefine the Ideas that were used as hypotheses, this time giving them absolute certainty. This movement = dialectic, which Plato learnt from Socrates.

Second, noesis is also the intellectual intuition, the state of knowledge in which we see the Good, all the other pure Ideas, and their systematic interconnections made possible by our vision of the Good.